Power actuated typewriter



1933- o. A. HOKANSON 1,921,159

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Aug. 8, 1933. 0. Av HOKANSON TYPEWRITER POWER ACTUAIED ,v 1925 3Sheets-Sheet Original Filed Sept.

Patented Aug. 8, 1933 UNITED STATES PATENT OFFICE POWER ACTUATEDTYPEWRITER Application September 2, 1925, Serial No. 54,039 Renewed Dec.26, 1929 9 Claims.

This invention relates to power mechanism for actuating the type barsand other parts of typewriting machines, and has for its object theprovision of such mechanism that will operate only at such time as isnecessary to move some part of the mechanism, that will make littlenoise, that will use a minimum of power, and that will be of improvedconstruction and operation.

The invention is exemplified in the combination and arrangement of partsshown in the accompanying drawings and described in the followingspecification, and it is more particularly pointed out in the appendedclaims.

In the drawings- Fig. 1 is a fragmentary vertical section of atypewriter having one embodiment of the present invention appliedthereto;

Fig. 2 is a fragmentary side elevation of the typewriter with the sidecover removed to show the actuating mechanism;

Fig. 3 is a fragmentary detail in top plan;

Figs. 4, 5 and 6 are details of parts;

Fig. 7 is a side elevation with the side cover in place;

Fig. 8 is a fragmentary front elevation showing the side cover in place;and

Fig. 9 is a fragmentary top elevation showing the side cover in place.

The numeral 10 designates the frame of a typewriting machine having atoothed roller 11 extending transversely of the frame and journaledtherein. A bar 12 also extends across the frame and carries a series ofpivoted sublevers 13 which engage and operate the type bars 14. Eachsublever 13 has an actuator 15 pivoted at 16 thereto and provided with ahook 17 for engaging the roller 11. A spring 18 holds the actuator in anupper retracted position. Adjustable screws 19 register with theactuators and disengage them from the roller at the end of their forwardstrokes imparted to them by the roller 11 for operating the type bars.The key levers 20 are provided with fingers 21 that move the actuatorsselectively into engagement with the roller 11. The mechanism thus farreferred to is more completely described in my prior application, SerialNo. 732,615 filed August 18, 1924, which application issued as PatentNo. 1,614,475, granted January 18, 1927, for an Improvement in poweractuated typewriters. v

In the present invention the roller 11 instead of being continuouslyrotated is given a step-bystep forward movement, the movement beinginaugurated by the depression of the key levers (c1. 197-1'zj that causethe actuators to engage the drive roller. The power for rotating theroller 11 is supplied by an electro-magnet 22 provided with a plunger 23which carries a pawl 24 pivoted to the plunger at 25 and drawn intoengagement with a toothed wheel 26 by' a spring 27. The wheel 26 isfastened to the roller 11 and is positioned outside of the side walls ofthe frame. The teeth of the wheel 26 are reversely directed relative tothe teeth of the roller 11. wheel 28 is secured to the wheel 26 at oneside thereof and engaged by a roller 29 carried on an arm 30 pivoted at31 on the frame. A lug 32 is secured to the arm 30 and a spring 33connects the lug 32 with a lug 34 on an arm 35. The spring 33 holds theroller 29 against the star wheel 28 to accurately position the wheel 26and roller 11. The arm 35 is pivoted at 31 and engages the pivot screw25 to move upwardly therewith when the solenoid is energized. An uprightarm 36 is formed integral with the arm 35 and has a fiber or othersuitable contact roller 37 adjustably secured to its upper end by aneccentric screw 38. The pawl 24 has a tailpiece 39 integral therewiththat strikes the ratchet wheel 26 at the upper limit of the stroke ofthe solenoid to prevent overthrow.

Current is supplied to the solenoid 22 through a contact plug 40 whichis connected through a switch 41 to a pair of contacts 42 and 43. Thecontact 43 is mounted on an insulation block 44 pivoted to the side ofthe frame at 45. The contact 42 is carried by a spring 46 mounted on theblock 44. A tappet roller 47 is carried on an arm 48 pivoted to theframe at 49. A spring 50 is secured to'alug 51 on the arm 48 and drawsthe tappet 47 toward the contact 42. The arm 48 has a tailpiece 52having a shoulder 53 engaged by a detent 54 on an arm 55 pivoted on arock shaft 56 extending across the frame of the machine. The detent 54when in engagement with the shoulder 53 holds the tappet 47 in retractedposition, as shown in Fig. 2. A second arm 57 shown in Fig. 4 is securedto a collar 58 joumaled on the shaft 56. A spring 59 draws the arms 55and 57 toward each other and their approach is limited by a lug 60 onthe arm 57 and a shoulder 61 on the arm 55. The arm 57 carries a detent62 arranged to engage a shoulder 63 on the tailpiece 52 but positionedadjacent the edge of the shoulder when the detent 54 is in engagementwith the shoulder 63.- The arm 55 has a tailpiece 64 which carries atooth 65 in the path of a lug 66 on an arm 67 carried by a collar 68secured to the shaft 56 We set screw 70. A spring A star 6 I1 normallydraws the arms 67 and 64 toward each other, but, the spring is attachedto a lug 72 on the arm and being stronger than the spring 71 holds thedetent 54 against the tailpiece 52. The shaft 56 carries a bar 73, Fig.l, which underlies projections 74 on the key levers 20.

Whenever any key lever is depressed the shaft 56 is given a partialrotation which moves the lug 66 against the tooth and carries said toothor lug 65 to the right, as shown in Fig. 2. This releases the detent 54and permits the spring 50 to move the tappet 47 to close the contacts 42and 43 and permits current to flow through the solenoid 22. The movementof the key lever also positions the corresponding actuator in front of atooth on the toothed roller 11 and when the solenoid is energized itmoves the roller one space to actuate the type bar corresponding to thekey lever depressed. The upward movement of the plunger 23 moves thecontact roller 37 against the tailpiece 52 and restores it to itsinitial position at the close of the plunger movement, thus opening thecontacts 42 and 43 and deenergizing the solenoid immediately upon thecompletion of its operation permitting the plunger to return to positionfor the next operation. Ordinarily the tailpiece 52 will be returnedbefore the key lever can be released so that the detent 54 will still beheld up out of the path of the shoulder 53. In this case the detent 62will engage the shoulder 63 and lock the tailpiece in itsrestoredposition until the key is released. The position will besufficiently retracted because of the oifset relation of the shoulders53 and 63 to permit the detent to move into position behind the shoulder53 when the key lever is released. The release oi. the key lever willretract the detent 62 from the shoulder 63 and transfer the holdingaction to the detent 54 preparatory to the next key depression. Thuseach stroke of the key positions the actuator, closes the circuit toenergize the magnet to impart a step of rotation to the power cylinder,automatically breaks the circuit at the close of the operation and locksthe contact closer in open position.

The contact block 43 is preferably adjustable toward and from the tappetto control the time in the movement of the plunger at which the circuitwill be broken and thus regulate the force of the type impression. Thisadjustment is effected by means of a lever '75 connected at 76 to a link77 having a pin '78 which projects through the side of the case andengages an inclined slot '79 in a plate 80 connected to the insulatorblock 44. This provides a simple and efficient arrangement forregulating the force of the impression. The lever may be provided withany desired number of positions determined by openings 81 in the curvedportion 82 oi. the casing for receiving the end of a pin 83 on theadjusting lever.

A cover plate 84 shown in Figs. 8, 9 and 10 encloses the actuatingmechanism and is provided with the proper contour to lit the variousparts. It will be seen from Figs. 8 and 9 that the mechanism is verycompact and does not project from the side of the machine any fartherthan the top plate of the ordinary hand-operated machine. It issometimes desirable to provide a condenser 85 in the electric circuit toprevent sparking at the contacts. The condenser may be connected inparallel with the solenoid, as shown.

I claim:--

i. The combination with a typewriter having type bars and key levers, ofa rotary power drive, key controlled means for selectively connectingsaid type bars with said power drive, a sole-.

noid having a plunger, ratchet mechanism for imparting limited rotarymovement to saidpower drive when said solenoid is energized to move saidplunger in one direction, a circuit for energizing said solenoid, aspring actuated tappet for closing said switch, a detent for holdingsaid tappet in retracted position, a key controlled device for releasingsaid detent, means actuated by said solenoid for retracting said tappetat the close of an operation of said solenoid, and means forautomatically retaining said tappet in retracted position.

2. The combination with a typewriter, of a power drive for saidtypewriter, a solenoid foroperating said power drive, a circuit forenergizing said solenoid, a spring actuated member for closing saidcircuit, a pair of detents for holding said circuit-closing means inretracted position, said detents being key controlled to release saidcircuit-closing means, and means operated by said solenoid forretracting said circuit-closing means, said detents operating to retainsaid circuit-closing means in retracted position irrespective oi theposition of the keys 01' said typewriter.

3. The combination with a typewriter having key levers and type bars, ofa solenoid for actuating said type bars, means controlled by said keylevers for operatively connecting said type bars with said solenoid, acircuit for energizing said solenoid, a switch for closing said circuit,a device operated by said keys for closing said switch, a movable blockon which said switch is mounted, and means for shifting said block tochange the position of said switch relative to its actuating device forcontrolling the closing period of said switch.

4. The combination with a typewriter, of electrically actuated means foroperating said typewriter, a switch for controlling said electricallyactuated means, a key controlled device for closing said switch, saidswitch being pivotally mounted on said typewriter for movement towardand away from said key controlled device, and a hand lever for shiftingthe position of said switch.

5. The combination with a typewriter having key levers and type bars, ofa power roller for actuating said type bars, a solenoid for impartingmovement to said power roller, actuators controlled by said key leversi'or connecting said type bars with said power. roller, a circuit forenergizing said solenoid, a switch movably mounted on said typewriterand interposed in said circuit, a spring actuated member for closingsaid switch, means for holding said member in retracted position, keycontrolled means 101' releasing said holding means, means Ior adjustingsaid switch toward and from said spring actuated switch-closing member,and means operated by said solenoid for resetting said spring actuatedswitch-closing member after the release of said holding means.

6. In a typewriter, the combination with a type bar, of a key lever,electric mechanism for operating said type bar, a switch for controllingsaid electric mechanism, an automatic switch actuator, latch mechanismfor holding said actuator out of operation, means operated by thedepression of said key lever to trip said holding means to cause saidactuator to operate said switch to effect the operation of the type bar,and means operated by said electric mechanism for restoring saidactuator and said switch to their non-operating positions independentlyof the position of said key lever.

7. In a type writer, the combination with a type bar, of a key lever,electroc-magnetic mechanism for operating said type bar, a switchcontrolled by the depression of said key lever for effecting theoperation of said electro-magnetic mechanism, and means comprising alever in an accessible position on the typewriter for adjusting theposition of said switch to regulate the type bar impression.

8. In a typewriter, the combination with a type bar, of a key lever, apower drive, means for connecting said power drive to said type bar upondepression of said key lever, electric mechanism for operating saidpower drive, a switch controlled by the depression of said key lever forefiecting the operation of said electric mechanism, and a lever in aposition accessible to the operator for controlling the timing of theoperation of said switch to regulate the impression of the type bar.

9. In a typewriter, the combination with a plurality of type bars, of aplurality of key levers, a power roller, means for connecting said powerroller to said type bars upon depression of said key levers, a solenoid,means connected between said solenoid and said power roller to drive thelatter, a switch for controlling the energization of said solenoid, anautomatic spring-actuated device for closing said switch, means forholding said device in retracted position, means connected to said keylevers for releasing said holding means to cause said device to actautomatically to close said switch, and means operated by the saidsolenoid for restoring said device to its retracted position and saidholding means to its holding position while said switch moves to openposition to effect de-energization of said solenoid.

OI'IO A. HOKANSON.

